Could it happen here?

The football authorities here were bemused by Europol's sudden announcement, but they and Uefa stress they do take the modern threat of match-fixing seriously.

The UK's professional football leagues jointly employ an agency to monitor betting markets around the world for suspicious patterns. Referees or other match officials may be changed before a match if unusual bets are placed, to remove any questions over their integrity. Lower-division matches are more likely to be targeted than those involving the multimillionaire players of the Premier League.

Rob Wainwright, Europol's director, was clearly intent on sounding the alarm over the English game, illustrated by his reference to the unspecified Champions League match played here which he said is under suspicion. Europol has not clarified which match it was, or whether, as reported by the Danish newspaper Ekstra Bladet, Wainwright was referring to Debrecen's 1-0 defeat at Liverpool in September 2009. Debrecen have confirmed their goalkeeper, Vukasin Poleksic, was questioned by Uefa after he was approached by match-fixers before that Liverpool game. However no action was taken, and there is no ongoing investigation.

Who are Europol?

A European Union agency whose role is principally to share information between police forces in EU member countries. "Europol officers have no direct powers of arrest but support EU law enforcement colleagues by gathering, analysing and disseminating information and co-ordinating operations," Europol say of their role.

Wainwright said Europol has formed a Joint Investigation Team, codenamed Veto, to coordinate Europe-wide operations against football match-fixing.

The investigations by the Bochum police in Germany, which produced the convictions of 14 people in 2011, centred on the Croatian ringleader, Ante Sapina, have been the most successful so far.

Many in football believe Europol was seeking to raise their profile by launching this week's sensational press conference, declaring 380 cases under suspicion in Europe and 300 more around the world. In 2011 Fifa gave Interpol, the international information-sharing agency, €20m to conduct a 10-year anti-match-fixing training initiative. Europol has no such partnership in football and is financed from the EU community budget; its 2011 budget was €84.8m.

What happens next?

Europol said Veto investigations are ongoing, although little further detail was offered. Friedhelm Althans, chief investigator for the Bochum police, said Europol does have evidence for 150 of the 300 matches suspected of being fixed worldwide. The football authorities in the major European leagues, and Uefa, will continue to spend money on anti-match-fixing but, with billions being bet on the Asian markets, their strategies are far from infallible.

There is general agreement with Ralf Mutschke, Fifa's head of security, that more co-operation is needed between law enforcement agencies and the football world.

Fifpro, the international footballers' union, points out that match-fixing has been most prevalent in lower divisions and eastern European leagues, where players are poorly paid and often have no written contracts, so are in theory more corruptible. Fifpro is calling for better employment conditions for footballers, and more education and training.

Why so relatively little money (for so many fixtures) involved?

Europol said that of the 380 matches in Europe, more than €8m was generated in betting profits and more than €2m paid in bribes to those involved in fixing the matches. This appeared principally to be made up of the operation uncovered by the Bochum police. The activities of Sapina's gang did mostly focus on lower division matches in Germany and eastern European countries, where comparatively small amounts of money can be enough to tempt football people.

Who is behind this?

Althams said the operations now under investigation are run out of Singapore. Europol emphasised that this is an extension of organised crime, so the conspirators can be from anywhere, but there has been a prevalence of Asian involvement.

Wilson Raj Perumal, who was identified as the head of a match‑fixing operation by organised crime investigators in Finland, is from Singapore. It has been reported that Perumal has disclosed information to Europol which led to its figure of 680 matches being identified.

Most of the betting on fixed matches is placed on Asian markets, which are less well regulated, and allow in-match betting on incidents in the games, rather than the results. Singapore police have stated their commitment to co-operating with European forces to counter match-fixing.

What are the chances of criminal convictions?

Difficult. The Bochum investigation is the prize operation so far, with convictions secured following telephone tapping and surveillance. Finland's organised crime investigators also scored a success in convicting Perumal and members of his operation.

Detecting bribery and corruption is anyway fraught, and proving an official or player acted deliberately to influence a football match is tricky.